1. Field of Invention
The present invention relates to a trench Schottky barrier diode (SBD) and a manufacturing method of an SBD; particularly, it relates to such SBD and manufacturing method wherein the breakdown voltage of the SBD is increased.
2. Description of Related Art
An SBD is a majority carrier device which has a high forward current and a very short recovery time because of a Schottky barrier generated by a Schottky contact which is formed between a metal layer and a semiconductor layer. However, a high leakage current is induced when a reverse bias is applied to the SBD, and therefore a trench SBD is invented. The trench SBD includes a semiconductor substrate with trenches, and a conductive material filled in the trenches, wherein the conductive material is separated from the semiconductor substrate by a dielectric layer therebetween. The trench SBD mitigates the high leakage current issue of the conventional SBD in a reverse bias operation by pinching off the reverse leakage current with a depletion region. However, when the trench SBD operates in a high voltage, a lower breakdown voltage of the trench SBD limits the application range of the trench SBD.
In view of the above, to overcome the drawback in the prior art, the present invention proposes a trench SBD and a manufacturing method thereof which provide a higher breakdown voltage so that the trench SBD may have a broader application range.